Anyone that has undergone surgery will tell you that the smaller the incision the less pain and the faster the recovery time. The ideal solution would be the ability to treat surgically without needing to cut into a patient at all.

As farfetched as though sounds, it is not an uncommon process. For instance, doctors have been using ultrasound waves for years to break kidney stones into sand like material that can be passed out of the body without requiring surgical intervention.

A biomedical engineer named Charles Cain from the University of Michigan has developed a new technique using ultrasound waves called histotripsy. This technique uses focused ultrasound waves 100 times more powerful than the ultrasound waves used for medical imaging during pregnancy.

These ultrasound waves are powerful enough to cause the formation of microbubbles in a process called cavitation that rapidly swell and collapse. Cavitation causes specific areas of diseased or unwanted tissue to liquefy. Researchers say that the liquefied tissue is then reabsorbed by the surround tissue of the body and recycled.

The interesting thing about using ultrasound in this type of process rather than laser is that ultrasound waves can travel several centimeters into the body without causing damage to tissue between the skin and the area of treatment.  Team member Zhen Xu describes the process as similar to that of burning paper with a magnifying glass and said, “You can focus the light waves into a focal point, and if you put paper there, you can set it on fire. But you are not going to set fire [to the space] in between."

The ultrasound beam is controlled via a joystick and the bubbles are easy to see on conventional ultrasound and MRI imaging allowing real-time monitoring of the process. Currently the process is being tested in animals and the team hopes to move to human trials in a few years.